DDR2 vs. DDR: Revenge Gained. Page 13

DDR2 memory tests, which we have performed earlier, showed that its higher latency is exactly the reason why it gets defeated by the regular DDR SDRAM. However, now the situation is changing. The leading memory manufacturers offer DDR2 modules with improved timings, which make DDR2 look completely different from what it used to be.

DDR2 SDRAM Modules for Enthusiasts: Overclocking

Besides testing the performance of various memory modules, we decided to check them at overclocking, too. We searched for the maximum frequencies DDR2 SDRAM modules were stable at, varying their timings. The tests were performed with an i925XE Express based P5AD2-E Premium mainboard. We set the memory frequency ratio to 4:3 relative to the FSB clock rate and were increasing the FSB clock rate until the system lost its stability.

The whole testbed looked as follows:

Intel Pentium 4 520J (LGA775, 2.8GHz) CPU;

ASUS P5AD2-E Premium (LGA775, i925XE) mainboard;

Sapphire RADEON X800 XT (PCI-E x16) graphics card;

Maxtor MaXLine III 250GB (SATA150) hard disk drive.

First of all we wanted to find the maximum frequency the modules could achieve with 4-4-4-12 timings and 1.9v voltage.

As you see, nearly all of the modules can work at frequencies above 667MHz. The exception if GeIL’s PC2-5300, but you can make them work at this frequency by setting CAS Latency to 5.

As for the leaders, the Corsair CM2X512-5300C4PRO modules, which have already confirmed their highest performance in overclocking modes, reach the highest frequency here. They are accompanied with the OCZ PC2 4200 Enhanced Bandwidth Platinum sticks which are not actually intended for high frequencies. In other words, the OCZ PC2 4200 Enhanced Bandwidth Platinum memory proves to be a versatile product, capable of working at high frequencies or at 533MHz with low timings.

Now let’s try the modules with 3-3-3 timings and 1.9v voltage.

The OCZ PC2 4200 Enhanced Bandwidth Platinum modules conquered the highest frequency at the aggressive timings, which is quite expectable. The remaining modules can only be clocked slightly above 533MHz with these timings, and the PQI25400 sticks couldn’t work with 3-3-3 timings at all.